Steady growth in air traffic volumes means Nav Canada will cut base rates for its air navigation services by an average of 3.5% and refund customers 4.6% of past fees starting Sept. 1, the private, not-for-profit Canadian company said.

The one-time refund will amount to about Canadian $60 million and includes taxes paid, the company said, adding that it also will be implementing a one-year rate reduction of 0.4%.

The Sept. 1 base rate cuts and one-time reduction, which comes at the start of the company’s fiscal year, cover commercial aviation customers. Cuts for general aviation kick in March 1, 2018, the start revision cycle for those charges.

The temporary cut extends one implemented last year. The cuts replace last year's 3.9% temporary rate reduction, which expires Aug. 31 (the end of the company's current fiscal year).

The changes become effective at the end of a mandatory 60-day consultation period that started when Nav Canada proposed them May 30.

“Higher than expected traffic growth this year has put us in a position to be able to pay the $60 million refund," Nav Canada President and CEO Neil Wilson said.

Nav Canada’s air traffic volumes increased more than 5% through the first nine months of the current fiscal year, which the company said continued the “steady and sustained traffic growth that we have seen over the past three years.”

Established in 1996, Nav Canada provides air traffic control, airport advisory services, weather briefings and aeronautical information services for more than 6.9 million square miles of Canadian domestic and international airspace. It is a founding partner of Aireon LLC, the international joint venture deploying a space-based ADS-B system.